Chain wrench

ABSTRACT

A chain wrench has an elongated handle which is connected to a jaw member through an eccentric. Rotational movement of the handle member relative to the jaw causes rotation of the eccentric and tightening of the chain around a pipe, tube, or similar article. Movement of the eccentric over its center position causes the wrench to be locked in position about the pipe. The degree of eccentricity of the eccentric is adjustable to vary the tightness of the chain around the pipe.

[111 3,805,646 Apr. 23, 1974 United States Patent [191 Knight 3,013,455 12/1961 Bettys........................... ..........81/69 CHAIN WRENCH [76] Inventor: Jesse R. Knight, RD. 1, Box 387 S,

Elizabethtown, Pa. 17022 Primary Exammer-James L. Jones, Jr.

Nov. 14, 1972 [2]] App]. No.: 306,401

Assistant Examiner-James G. Smith [22] Filed:

Attorney, Agent, or Firm-Jay L. Seitchik [57] ABSTRACT A chain wrench has an elongated handle which is connected to a jaw member throu gh an eccentric. Rotationai movement of the handle member relative to the jaw causes rotation of the eccentric and tightening of the chain around a pipe, tube, or sim Movement of the eccentric over its cen causes the wrench to be locked in pipe. The degree of eccentricity of 12 39 1/ 6 9 91 oo 6 ,6 Anus .6 $37 .54 0 0 m A 6 2 3 H 5 8 mm mu.. "mu mmm4 HUB mmn7 h m 1 mnmoo e M ll f C d 5mm UIF 1:11 2 8 555 121i i1ar article. ter position position about the the eccentric is ad- S T. N m g T 3 ms e D E n N U m w justabie to vary the tightness of the chain around the pipe.

269/131 Se1fr1dge....... 81/69 Schweitzer.............................. 81/69 9 Claims, 8 Drawing Figures U D 1110 356 999 111 l// 72 PATFNTEnAPR 23 mm SHEEI 1 UF 1 m L ||11|l i r l CHAIN WRENCH BACKGROUND OF THE INVENTION This invention relates to wrenches of the type usable on pipes, tubes, or similar articles.

Conventional forms of pipe wrenches presently in use employ a pair of jaw members which function to grip a pipe therebetween and to bite into the pipe thereby permitting the operator of the wrench to rotate the pipe in a desired direction. Wrenches of thistype have several drawbacks. These wrenches rely on squeezing pressure between the jaws for their connection to the pipe and therefore it is necessary that the jaws bite into the outer surface of the pipe. This marring of the pipe surface is often undesirable and may serve to weaken the pipe, remove outer protective coverings, and in some instances to actually render the pipe unsuitable for further use. A further problem with conventional wrenches is that their size and jaw configuration renders them suitable for only a limited range of pipe sizes, therefore requiring an operator to stock several such wrenches in order to have the ability to work on a wide variety of pipe sizes.

OBJECTS AND SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide an improved wrench which is usable on pipes, tubes, or similar articles without marring the surface thereof.

Another object of the present invention is to provide an improvedwrench which is capable of being locked in position around a pipe and which is capable of retaining itself in such position; I

A further object is to provide an improved wrench which is adjustable to vary the degree of gripping pressure between the wrench and the pipe or similar article.

Another object of the present invention is to provide a wrench which can be used in ratchetting fashion in those instances where there is insufficient room to continually rotate the wrench about the pipe.

A still further object of the present invention is to provide a wrench which is usable with a wide variety of pipe sizes without sacrificing the efficiency of the wrench operation.

In accordance with the above objects, the wrench of the present invention comprises a jaw member and a gripping chain cooperable to wrap around a pipe disposed therebetween. The chain is connected to a handle member through an eccentric mechanism which is movable to an over-center position thereby to lock the chain in gripping position about a pipe. The degree of pressure exerted by the chain around the pipe is adjustable by varying the degree of eccentricity of the eccentric mechanism. By providing a gripping surface entirely around the pipe there is minimized the risk of damage to the pipe through marring or crushing or the like.

BRIEF DESCRIPTION OF THE FIGURES In the drawings, in which like reference numerals refer to like parts:

FIG. 1 is a perspective view of a chain wrench constructed in accordance with the teachings of the present invention;

FIG. 2 is a perspective view showing the wrench of FIG. 1 in tightened position around a pipe;

FIG. 3 is an exploded perspective view showing the various parts of the wrench of FIG. 1;

FIG. 4 is a fragmentary cross-sectional view taken along the line 4--4 of FIG. 3;

FIG. 5 is a cross-sectional view of the wrench of FIG. 1 showing the operative parts in their rest position; FIG. 6 is a cross-sectional view similar to F IG. 5 and showing the wrench loosely positioned around the pipe;

FIG. 7 is a view similar to FIG. 6 and showing the wrench in its tightened position; and

FIG. 8 is a cross-sectional view showing an alternative embodiment of the present invention.

DETAILED DESCRIPTION With reference now to the drawings there is shown wrench indicated generally at 10 having an elongated handle member 12 which is shown as a hollow tubular member and provided intermediate its ends with a nut member 14 having internal threads thereon and being suitably secured to the handle 12. Disposed within handle 12 is an elongated rod 16 (See FIG. 5), the rod being threaded at its lower end 18 for cooperation with the nut 14 of the handle member. The end of rod 16 opposite to the threads 18 is bifurcated as shown in FIG. 3 to provide a pair of extensions 20 and 22, each of the extensions having an aperture 24 therethrough fora purpose to be described. Rod 16 and handle member 12 are coaxial and are movable longitudinally relative to each other by rotation of the handle memberrelative to the rod.

Disposed within the upper portion of handle 12 is a coupling member 26 of generally T-shaped configuration and best seen in FIGS. 3 and 4. The coupling mem ber has a lower tubular portion 28 having an outside diameter slightly less than the inside diameter of handle 12 so that the tubular portion is receivable within the handle member and slidable relative thereto. The portion 28 has a hollow interior as-indicated at 30 f0 receiving therein the major portion of rod 16. Rod 16 is axially movable relative to the coupling member 26 and there may be provided a bushing 32 to facilitate relative sliding movement between the coupling member and the rod 16. The coupling member has a generally cylindrical upper portion 34 having an axis at right angles to the axis of portion 28. A pair of end caps 36 and 38 are provided at opposite ends of cylindrical portion 34 and each end cap is provided with a radially extending slot 40 which extend along lines which are parallel to the axis of tubular portion 28. The end caps 36 and 38 are secured tocylindrical portion 34 by any suitable means such as welding or the like.

A shoulder 42 is provided on the portion 28 and is arranged to abut the upper end of handle 12 when the coupling member 26 is disposed in position within the handle.

The cylinder 34 has an opening 44 disposed generally midway between end caps 36 and 38 and extending for approximately around the circumference of cylinder 34. The opposite surface of cylinder 34 from opening 44 is provided with an abutment 46 extending radially outwardly from the cylinder for a purpose which will be more apparent hereinafter.

A suitable length of chain 48 is provided and is connected at one end to a link 50 which has one end suitably secured to the chain and has a second endwhich extends through opening 44 and has a circular opening 52 disposed within the interior of the cylindrical portion 34 of the coupling member.

Referring now-to FIG. 3 there is shown in detail the jaw member indicated generally at 54. The jaw member ma be conveniently formed as a casting and has an upper portion 56 which is of arcuate configuration and is provided with a pair of grippers 58 secured thereto by any suitable means. The grippers have their upper surfacesserrated so as to be capable of firmly engaging a tube or pipe or similar article. The lower portion of jaw member 54 comprises an annular bearing member 60 and a split bearing member 62 and 64, the members 62 and 64 being provided with flanges 66 which receive threaded fasteners 68 for securing the bearing members 62 and 64 together.

The wrench of FIGS. 1 through 7 is assembled by inserting rod 16 into handle l2 and by placing the coupling 26 over the rod 16 and within the upper portion of handle 12. The jaw member 54 is then slid over the cylindrical portion 34 of the coupling member. Securing the split bearing member 64 to member 62 will retain the jaw member in position on the coupling member. Replacement of the jaw member is thus easily affected by removing the fastener 68 to separate the split bearing member to thus permit the use of different size jaw members or to permit replacement of a jaw membet in the event that damage should occur. After the jaw member 54 is secured in position the link 50 is inserted through opening 44 and an elongated bolt 70 is inserted through the slots 40 of each caps 36 and 38 through the opening 52 in link 50. The opening 52 of the link is'disposed between the bifurcated rod extensions 20 and '22 of rod '16v and therefore the bolt also passes through the apertures 24 formed in the extensions. A nut 72 is then threaded onto the end of bolt 70 to complete the assembly. With the tool thus assembled it can be seen that rotation of the handle 12 will cause axial displacement of rod 16 thus causing the bolt 70, extending through the end of rod 16, to move within the slots-40 thuschanging the position of the bolt relative to the cylindrical member 34. The purpose of this movement will become apparent as the description proceeds The operation of the wrench will now be explained with particular reference to FIGS. 5 through 7. FIG. 5 shows the wrench with the movable parts in their position at the start of an operating cycle. When it is desired to apply the wrench to a pipe the chain 48 is grasped and moved around the outer periphery of a pipe 74 as shown in FIG. 6. It can be noted that the pipe 74 is surrounded on one side by the chain and on the opposite side by the grippers 58. The chain is loosely surrounding the pipe at this point in the cycle and a link of the chain is inserted between a pair of projections 76 provided on the upper portion 56 of the jaw member. The projections are of an appropriate size and shape so that a chain link may be disposed between the projections and maintained in position by cooperation of the pins 78 of the chain and the sides of projections 76. At this point the handle member 12 is moved in a counterclockwise directionas shown by the arrow in FIG. 7 and such handle movement causes the rod 16 to exert a pulling force on link 50 thus causing tightening of the chain about the pipe. It can be seen that the bolt 70 which connects the rod 16 to link 50 is eccentrically located within the cylindrical member 34 and thus continued rotation of the handle will cause continued tightening of the chain until the bolt moves to an overcenter position as shown in FIG. 7 by the angle a. This movement ,to an over-center position causes the wrench to be locked in a tightened position around the pipe and enables the wrench to maintain itself about the pipe in a manner such as shown in FIG. 2 of the drawings. The operator can release the wrench entirely without fear that the wrench will fall or that the grip on the pipe will be diminished.

The extent of movement of the handle 12 is limited by engagement of the abutment 46 with the undersurface of portion 56 as shown in FIG. 7. Continued counterclockwise movement of, the handle causes the pipe 74 to be turned under the gripping influence of the grippers 58 and the chain 48. The pipe is not crushed or marred during this operation because the gripping force is distributed over a major portion of the outer surface of the pipe rather than being centralized at only a few points as is the case with conventional wrenches.

When the operator rotates the wrench from the position of FIG. 6 to that of FIG. 7 he may detect that the chain'is too loose or too tight around the pipe. This may result because many size pipes may be used and the chain is limited in its versatility by the dimension between-the pins 78 of each chain link. However, the wrench of the present invention is infinitely adjustable due to the ability of the operator to rotate handle 12 thus changing the degree of eccentricity thereby changing the effective length over which link 50 is pulled during handle movement. The operator can therefore ad- I just the handle until he feels proper tension in the tool during movement to the over-center position.

It will also be apparent that it is unnecessary to continually rotate the tool in order to rotate the pipe 74. The tool'can be used in a ratchetting fashion because each clockwise movement of the handle will cause loosening of the chain 48 thereby allowing the tool to slip around the pipe in readiness for the next counterclockwise movement of theme! during theoperating cycle. This feature is of extreme importance when the tool is being used in confined areas where there is insut ficient room to spin the handle through 360.

With reference to FIG. 8 there is shown a modified form of the present invention. Those parts which are identical to the form of FIGS. 1 through 7 have been assigned the same reference numerals as previously described. The tool of F IG. 8 is more suitable for use with very large diameter pipes and is provided with a generally U-shaped yoke member 80 connected at its ends to bolt 70 in straddling relationship to the jaw member and coupling member. The opening 44 of the FIG. 1 form is unnecessary in this embodiment. The opposite end of yoke 80 is provided with a collar 82 which is rotatably mounted on the. yoke member and which is secured by suitable means to the end of chain 48. Operation of the tool of FIG. 8 is identical to that of the tool previously described in that the arms of yoke member 80 perform the same function as link 50. The yoke member 'of FIG. 8, however, does permit the end of the chain to be further removed from the eccentric axis defined by bolt 70 thus moving the chain to a position where larger diameter pipes may be encircled. This further insures that no damage to the pipe will result during tightening of the tool in an operating cycle.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only.

What is claimed is:

l. A wrench for use with pipes or similar articles, said wrench comprising an elongated cylindrical handle member, a jaw member, means on said jaw member for engaging a workpiece, a coupling member for operatively connecting said jaw member to said handle member, said coupling member having a first cylindrical portion disposed with its axial generally normal to the major extent of said handle member, bearing means on said jaw members cooperating with said first cylindrical portion whereby said jaw member and coupling member are rotationally mounted relative to each other, said coupling member further having a second cylindrical portion disposed with its axis generally parallel to the major extent of said handle member, said coupling member and said handle member being rotationally mounted relative to each other about the axis of said second cylindrical portion, a chain-like member, link means secured to one end of said chain-like member, retaining means on said jaw member for retaining a portion of said chain-like member displaced from said one end, pin means eccentrically mounted within said first cylindrical portion of said coupling member, said pin means operatively connecting said link means to said handle member, whereby arcuate movement of said handle member relative to said jaw member causes movement of said chain-like member relative to said jaw member, and adjustment means connecting said pin means to said handle member for altering the degree of eccentricity of said pin means relative to said first cylindrical portion of said coupling member, said ajustment means being effected by rotation of said handle member relative to said second cylindrical portion of the coupling member.

2. A wrench as set forth in claim 1 whereby said eccentrically mounted pin means is movable to an overcenter position to thereby retard movement of said wrench from an operative to an inoperative position.

3. A wrench as set forth in claim 2 further comprising abutment means on said coupling member engagable with said jaw member for limiting relative rotational movement therebetween.

4. A wrench as set forth in claim 1 wherein said adjustment means comprises an elongated rod member having one end connected to said pin means and having a second end which is threadably connected to said handle member whereby rotational movement of said handle member about its longitudinal axis causes relative axial movement between said rod member and said handle member.

5. A wrench as set forth in claim 4 wherein said workpiece engaging means comprises a pair of gripping members securkd to said jaw member and having a serrated surface thereon.

6. A wrench as set forth in claim 1 wherein said first cylindrical portion has a peripheral opening provided in the central portion thereof and wherein said link means extends through said peripheral opening.

7. A wrench as set forth in claim 1 wherein said first cylindrical portion is provided with end caps having radial slots therein and wherein said pin means'extends through said slots, said adjustment means causing said pin means to move along said radial slot.

8. A wrench as set forth in claim 7 wherein said link means comprises a yoke member secured to said pin means externally of said end caps. i

9. A wrench as set forth in claim 7 wherein said radial slots are aligned with the longitudinal axis of said handle member. 

1. A wrench for use with pipes or similar articles, said wrench comprising an elongated cylindrical handle member, a jaw member, means on said jaw member for engaging a workpiece, a coupling member for operatively connecting said jaw member to said handle member, said coupling member having a first cylindrical portion disposed with its axial generally normal to the major extent of said handle member, bearing means on said jaw members cooperating with said first cylindrical portion whereby said jaw member and coupling member are rotationally mounted relative to each other, said coupling member further having a second cylindrical portion disposed with its axis generally parallel to the major extent of said handle member, said coupling member and said handle member being rotationally mounted relative to each other about the axis of said second cylindrical portion, a chain-like member, link means secured to one end of said chain-like member, retaining means on said jaw member for retaining a portion of said chainlike member displaced from said one end, pin means eccentrically mounted within said first cylindrical portion of said coupling member, said pin means operatively connecting said link means to said handle member, whereby arcuate movement of said handle member relative to said jaw member causes movement of said chainlike member relative to saId jaw member, and adjustment means connecting said pin means to said handle member for altering the degree of eccentricity of said pin means relative to said first cylindrical portion of said coupling member, said ajustment means being effected by rotation of said handle member relative to said second cylindrical portion of the coupling member.
 2. A wrench as set forth in claim 1 whereby said eccentrically mounted pin means is movable to an over-center position to thereby retard movement of said wrench from an operative to an inoperative position.
 3. A wrench as set forth in claim 2 further comprising abutment means on said coupling member engagable with said jaw member for limiting relative rotational movement therebetween.
 4. A wrench as set forth in claim 1 wherein said adjustment means comprises an elongated rod member having one end connected to said pin means and having a second end which is threadably connected to said handle member whereby rotational movement of said handle member about its longitudinal axis causes relative axial movement between said rod member and said handle member.
 5. A wrench as set forth in claim 4 wherein said workpiece engaging means comprises a pair of gripping members securkd to said jaw member and having a serrated surface thereon.
 6. A wrench as set forth in claim 1 wherein said first cylindrical portion has a peripheral opening provided in the central portion thereof and wherein said link means extends through said peripheral opening.
 7. A wrench as set forth in claim 1 wherein said first cylindrical portion is provided with end caps having radial slots therein and wherein said pin means extends through said slots, said adjustment means causing said pin means to move along said radial slot.
 8. A wrench as set forth in claim 7 wherein said link means comprises a yoke member secured to said pin means externally of said end caps.
 9. A wrench as set forth in claim 7 wherein said radial slots are aligned with the longitudinal axis of said handle member. 